A number of pains, cramps and convulsive disorders are caused by an insufficient or non-uniform blood flow in the outer skin. In many cases alleviation, improvement or even healing may be achieved by a uniform application of heat. The treatment with infrared radiation, warming bottles, heating pads, hot packs and cataplasms always involves considerable trouble and therefore is not always or readily practicable.
It is also known that transdermally absorbable active substances such as, more specifically, oils of officinal herbs, are therapeutically active, particularly when they can display their action over a sufficiently long period of time and have the opportunity of penetrating into the skin. There has already been a long search for possibilities of enhancing the efficiency of the transdermally absorbable active substances.
From the EP-A- 0 0163 045 there are known means for heat insulation and distribution, more specifically of heat of the body, on areas of the outer skin which means consist of a laminate comprising a foam layer, a flexible heat-conducting metal layer and a further foam layer These means have already proven to be valuable in the form of warming plasters, pads, mats etc.